Add extra init and default branch to bypass "maybe unitialized" error

Author: pwilkin

ggml/src/ggml-cpu/vec.h

@@ -1427,12 +1427,13 @@ inline static void ggml_vec_sum_f32(const int n, float * s, const float * x) {
 //   type         - type of triangular mask (lower, upper, etc.)
 inline static void ggml_vec_tri_f32(const int n, const int r, float * dst, const float * src, bool keep_org_val, float c, enum ggml_tri_type type) {
     for (int i = 0; i < n; ++i) {
-        bool cmp;
+        bool cmp = false;
         switch (type) {
             case GGML_TRI_TYPE_LOWER: cmp = i < r; break;
             case GGML_TRI_TYPE_LOWER_DIAG: cmp = i <= r; break;
             case GGML_TRI_TYPE_UPPER: cmp = i > r; break;
-            case GGML_TRI_TYPE_UPPER_DIAG: cmp = i >= r; break;
+            case GGML_TRI_TYPE_UPPER_DIAG: 
+            default: cmp = i >= r; break;
         }
         dst[i] = cmp ? (keep_org_val ? src[i] : c) : 0.0f;
     }